Building system faults are often difficult to diagnose. As a result, many building systems, such as heating and air conditioning systems, run in undesired operating ranges leading to discomfort for building tenants or occupants and/or run in ways that interfere with operation of a highly efficient building. Underperformance of building components is a common and widespread contributor to poor energy efficiency, which can significantly increase operating and energy costs for the building. Such costs quickly multiply for organizations managing operation of large numbers of buildings that may be located throughout a geographically dispersed area, with the size of buildings and their widespread locations making central and coordinated management more difficult.
Underperforming building systems and equipment often go undiagnosed by building maintenance personnel because each component is typically a small part of a much larger and more complex system (e.g. changing a setting of one fan or one heating unit can affect other components and conditioned building zones), because the training of building owners and equipment operators is lacking or simply inaccurate, or because the commissioning, diagnostic, and maintenance procedures provided for identifying an underperforming or “broken” piece of building equipment is difficult to execute.
Recently, there has been a growing urgency to operate building systems with more energy efficiency such as with automated control and monitoring of heating, ventilation, and lighting needs of a building or group of buildings such as office buildings, factories, educational campuses, retail malls, and the like. To increase efficiency and try to identify the underperforming or broken system components or systems, many building owners or operators have implemented building management systems (or energy management systems (EMSs)). Building management systems are computer-based control systems installed in buildings to monitor and control one or more of the buildings' mechanical and electrical equipment such as ventilation, lighting, and power systems. Some estimates have indicated that the systems linked to and controlled by a building management system may represent 40 percent of a building's energy usage and may represent up to 70 percent of the energy usage when lighting is included. Even small improvements in the effectiveness of a building management system can provide large improvements in energy efficiency and cost savings for operating a building.
As one exemplary function, a building management system may control heating and cooling including managing the systems that distribute air throughout a building. This may involve remotely controlling operation of fans, opening/closing dampers, adjusting a temperature setting on a cooling or heating unit, and so on to try to achieve a desired room temperature. The building management system (or building EMS) receives data from numerous sensors on or near system components and stores this monitored data in a management database (e.g., air flow rate in a ventilation duct downstream of a damper, a temperature in a building space, a setting of a heating or cooling unit). The building management system may then process this received data to operate one or more components or to identify a fault condition that may require maintenance.
Unfortunately, there are a number of issues with existing building management systems. Due to the large number of monitored components and possible fault conditions, many faults or alerts that may indicate an underperforming piece of equipment are simply ignored or left unchecked/unresolved. For example, the sensor information may indicate that a building space is out of a desired temperature range, but, unless there are occupant complaints, the building operator, with limited resources and time, may ignore this alert even though it may indicate a piece of equipment is operating inefficiently (e.g., too much cooling or heating being used).
Another problem arises when a building operator attempts to tune or adjust operation or to perform diagnostics on a piece of building equipment. Often, the building management system has to be accessed via a terminal at or linked to the data storage device storing the management database. For example, a worker may be required to type in a particular component identifier for the equipment or system in question, such as by retrieving building drawings and then entering a specific variable name associated with the component into a user interface screen. This may result in the building management system providing the worker with the operating data for the component received from monitored sensors, and the worker can then print out or write down this data for use in making adjustments or diagnostics on the component. If tuning or operational testing is required, a second worker may be sent to a remote location in the building to operate a controller on the component or piece of equipment or to make a series of measurements while the first worker remains at the building management system terminal. The two workers communicate via wireless devices (e.g., radios, cellular phones, or the like) to determine if adjustments or tuning has desirably changed the operation of the system (e.g., by partially closing a valve did this cause the temperature in a duct or building space to move into a desired range?). This trial and error approach combined with the need of two workers is generally inefficient and sometimes ineffective in tuning the component to work efficiently or in properly performing component or system diagnostics.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.